The following diseases are clinically possible: the first one is the sebaceous cyst under the earlobe. This is particularly common clinically, mainly because the secretion of the sebaceous glands is blocked and the secretions of the glands are constantly retained, resulting in the expansion of the cystic skin and the formation of cysts. Once there is no local infection, it may be a painless mass, but once it is locally infected, there may be painful flow of pus, rupture and other related changes. The second type is inflammation of the parotid gland. The main manifestation is localized redness, swelling and pain, and the patient may have fever. It is not difficult to diagnose by ultrasound of the parotid gland and serum amylase. The third type of tumor in the parotid gland is usually a painless mass that gradually increases in size. This can be diagnosed clinically by ultrasound of the parotid gland and CT of the parotid gland.